The proposal is to continue a training program in cancer research at Columbia University that was established in 1984. The rationale of the Cancer Biology Training Program is to identify and recruit individuals with outstanding potential and prepare them for highly productive careers in cancer research. This will be achieved by offering a rigorous didactic curriculum, providing opportunities for cancer research in the laboratories of Columbia University faculty, and fostering an interactive environment in which trainees can gain exposure to the full range of scientific disciples involved in cancer research. Funds are requested to support 6 postdoctoral and 4 predoctoral trainees annually. Training is provided by a Program Faculty comprised of 37 independent cancer scientists, most of whom are well funded by grants from the NCI (and other cancer-focused organizations) and highly productive in terms of cancer research. The participating faculty are selected on the basis of the cancer focus and quality of their research programs, their record of productive interactions with other cancer investigators, and their experience in training postdoctoral fellows and predoctoral students. The Predoctoral and Postdoctoral Trainees are chosen competitively according to the cancer focus and quality of their proposed research project, their past academic and research performance, their future potential as independent investigators, and their commitment to a career in cancer research. The Cancer Biology Training Program has benefited greatly from a recent expansion of cancer research at Columbia University Medical Center. This expansion was driven by the opening in 2005 of the Irving Cancer Research Center, a new 300,000 square-foot 10-story building devoted entirely to cancer research, and the continuing recruitment of leading scientists in the basic/translational, clinical and population arenas of cancer research. These developments have broadened the scope and enhanced the quality of the Cancer Biology Training Program, as well as attracted a superior pool of trainees seeking careers in cancer research.